The present invention relates to weight-measuring devices and more particularly to an air-driven hydraulic weighing system.
Spools of paper are weighed as one step of the paper-manufacturing process. Different types of scales are employed to perform this weighing step. Some of these scales are completely mechanical in nature. Others employ hydraulic systems using electric motors to pump the hydraulic fluid. Others require that the spools of paper be removed from the processing line in order to be weighed.
The known systems have known drawbacks. Mechanical scales require continuous maintenance because of the number of moving parts which such scales include. Because any mechanical scale is subject to wear, it must also be recalibrated periodically by taking the scale out of service and using it to weigh a reference load.
Hydraulic systems having electrically-powered fluid pumps also require a relatively high level of maintenance as well as periodic recalibration.
Of course, if the scale is of a type which requires that the paper to be weighed be diverted from the processing line, the manufacturing process is necessarily slowed by the weighing step.